1. Field of the Invention
The invention is in the general field of materials which are suitable for use as additives in lubricating oils. In particular, the invention is in the field of materials which provide lubricity, oxidation inhibition, and dispersancy in lubricating oils.
2. Background
Various materials have been used in lubricating oils for many years. These materials known as "lube additives" serve a variety of functions. For example, compounds containing phosphorus, sulfur, or chlorine and combinations thereof have been used as lubricity agents. This type of material serves to improve the load-carrying property of the lubricant. Other materials, such as zinc thiophosphates, phenols, and aryl amines, are known which improve the oxidation stability of lubricants. Still further, other materials have been used to impart a dispersancy property to lubricants. These materials serve to disperse wear products and other foreign materials in the lubricant.
For many years various types of oil-soluble sulfonates have been used as dispersants in lubricants. The preferred oil-soluble sulfonates have been the barium and calcium sulfonates. More recently, an interest has developed in the use of dispersants which do not contain any metal. This latter type of dispersant is referred to as an "ashless dispersant." A particularly preferred type of ashless dispersant contains the polyalkyleneamine moiety. Unfortunately, this type of material is inherently unstable to oxidation.
I have discovered certain novel compounds which, when used in lubricating oils, impart lubricity, oxidation inhibition, and dispersancy to the lubricating oils.
3. Prior Art
An IFI-Plenum computer search failed to produce a reference disclosing the novel compounds of my invention. Also, a search by a Washington searcher failed to produce a reference disclosing the novel compounds of my invention or the process of preparing them. For the record, the Washington searcher did call attention to the following patents which are of general interest: U.S. Pat. Nos. 2,552,574; 3,244,586; 3,286,002; 2,411,527; 2,615,037; 2,865,948; and 3,733,379.